The present invention relates to a starter circuit for motors, particularly for refrigerator compressors. More particularly, the invention relates to a starter circuit for asynchronous motors, particularly but not exclusively adapted for motors of refrigerator compressors, both for industrial and household applications.
It is known that in a refrigerator the compressor is activated periodically so as to pump the coolant in the coils of the refrigerator.
This activation of the compressor occurs when the internal temperature of the refrigerator rises above a preset threshold. Accordingly, a heat-sensitive element detects the internal temperature of the refrigerator, and when said temperature rises above the set threshold it sends an activation signal to a compressor starter circuit. The starter circuit comprises a starter is and a protector for the motor of the compressor.
The starter is constituted by a heat-sensitive element in which the flow of current produces a temperature increase which causes the element to behave like a resistor having a very high value. Since such resistor is arranged in series to the motor, the temperature increase prevents the flow of current through the heat-sensitive element in order to reach the starter winding of the motor of the compressor.
However, although the heat-sensitive element is effective from the point of view of the intermittent activation of the single-phase asynchronous motor of the compressor, it entails a continuous, albeit modest, power consumption throughout the period during which the motor is running.